                         0
                         (/ 1 (+ (/ 1 addition-rate) 1)))
         after-addition (vec (apply concat
-                                   (map #(if (< (lrand) addition-rate)
-                                           (lshuffle [% 
-                                                      (random-plush-instruction-map 
-                                                        atom-generators argmap)])
-                                           [%])
-                                        (:genome ind))))
+                                   (mapv #(if (< (lrand) addition-rate)
+                                            (lshuffle [% 
+                                                       (random-plush-instruction-map
+                                                         atom-generators argmap)])
+                                            [%])
+                                         (:genome ind))))
         new-genome (vec (filter identity
-                                (map #(if (< (lrand) deletion-rate) nil %)
-                                     after-addition)))]
+                                (mapv #(if (< (lrand) deletion-rate) nil %)
+                                      after-addition)))]
     (make-individual :genome new-genome
                      :history (:history ind)
                      :age (inc (:age ind))

                        (/ 1 (+ (/ 1 combination-rate) 1)))
        after-combination (vec 
                            (apply concat
                                   (map (fn [g1 g2]
                                          (if (< (lrand) combination-rate)
                                            (lshuffle [g1 g2])
                                            [g1]))
                                        (:genome parent1)
                                        (cycle (:genome parent2)))))
        new-genome (vec (filter identity
                                (map #(if (< (lrand) deletion-rate) nil %)
                                     after-combination)))]
    (make-individual :genome new-genome
                     :history (:history parent1)
                     :age ((age-combining-function argmap) parent1 parent2 new-genome)

        :is-random-replacement
        (if use-child false true)))))

